How to merge expense lines and tax lines coming from corporate card feed for foreign transactions?

In India, whenever we use corp cards for expense while travelling abroad, for each foreign transaction, there will be GST lines added as separate line item.. So 10 expense lines will getting 30 lines in total (2 lines each for CGST/SGST).
We are trying to merge these two GST lines into a single line while loading a corp card transaction with corresponding expense line itself but we are not able to merge.
Can you please provide a solution to merge these lines in a single line while loading a feed from Corp Card.